基于零电压开关的超级电容均压技术

Super-capacitor Voltage Equalization Technology Based on Zero-voltage Switching

为了减少超级电容均压过程中开关器件的开关损耗,提高能量利用率和均压效率,提出了一种新型的基于零电压开关(ZVS)的超级电容均压电路。分析了电路在不同开关状态下的工作原理,推导了其不同工作阶段中电压电流的关系,建立了电路的时域电压电流模型,并分析了不同参数对电路工作特性的影响,得出了新型均压电路关键参数的设计原则,通过计算得出可以实现零电压开关的条件,利用图示法表示零电压区域。仿真和实验结果证明该方法真正实现了零电压开关,均压效率超过80%,开关损耗减少75%,显著降低了开关损耗,适用于储能系统中串联超级电容器或者蓄电池的均压。并且可以基于该均压电路为基本拓扑进行扩展,便于应用在电力系统、新能源发电中的大规模储能系统,具有较高的应用价值和较好的发展前景。

In order to reduce the switching loss of the switching devices during the switching process of super capacitors, and to improve the efficiency of voltage equalization and energy utilization, a novel type of super capacitor voltage equalization circuit based on zero voltage switching（ZVS） is proposed. Details of the operation principles were introduced, relationship of voltage and current in different work process was analyzed. A time domain model of voltage and current of the circuit was found, and the effects of different parameters on the working characteristics of the circuit was analyzed, the principle of designing key parameters of a new type of voltage equalization circuit was given, zero voltage switching condition was obtained by calculation, using the diagrammatic representation of zero voltage region. The simulation and hardware experiment were implemented. Results show that the method realizes real zero voltage switching process, the efficiency of the equalization method is more than 80%, and switching loss decreased by 75%, which reduces the switching loss significantly and is suitable for the series super-capacitors or batteries in energy storage system. Based on the general topology model of multilevel converter, the circuit can be expanded and convenient for applications in large-scale storage system, which is widely used in electric power systems, new energy and other fields, with a high value and great prospects for development.